I bought a rotary tumbler and put aluminum chips in there with steel balls and iso alcohol (dry aluminum dust is an explosive risk apparently).
The issue is the process takes forever (over 48 hours so far) and it’s not effectively crushing up the chips.
My next attempt I’m going to be using a “vibrating plate exercise machine” base with an enclosure strapped onto it filled with the mix. That way I can add tons more steel balls and it has a powerful motor driving everything.
I want this powder to use for inlays. I have probably 50lbs of chips on hand and don’t want to pay for pre-made aluminum powder (even though it’s more safe and stable).
Just wondering if anyone has advice or tips for making this powder?
I’m thinking of trying a coffee grinder or magic bullet next if I can’t get the vibrating machines to work.
Question: Why alcohol. That is also an explosion risk.
Steel balls will likely burnish or polish aluminum without breaking it down much. I don’t know any abrasive media that won’t also break itself down overtime in a tumbler, thus contaminating your aluminum. Maybe ask the internet/ChatGPT. Could also need a completely different process, kind of like how flour/grain mills grind material.
My guess is that repurposing those chips like that isn’t going to be worth the effort. You’d be better served taking a scrap block of aluminum and ramming it into a belt sander.
Aluminum powder is a component of thermite (used for welding underwater among other things).
Ball mills (used in labs) are horrendously noisy and really only work on things that will fracture. Likely you may make some small foil bits or even build bigger pieces. The things that may get you powders will likely be more costly than selling the chips for scrap and buying the powder. Do you need 50 lbs of aluminum powder? Thoughts I had were dissolve and repreciptate (chemically or electrolytically) melting (or just compacting) the chips into a bigger solid and using a grinder. Counting your materials and time that seems the costly route
Yea the alcohol is flammable, but I think the idea was that keeping everything wet will stop any dust, sparks or oxygen based combustion (according to AI at least). I ran a super small batch in a 3lbs tumbler for 24 hours straight with no issue. At the end it will vaporize and disappear leaving clean aluminum remaining. It definitely feels a bit sketchy for sure though.
I don’t mind some steel contamination since it’s just for inlays.
Might just buy some powder and save the chips for a future forging project or something. Doing a quick test run with 15lbs of steel balls and a very small batch of aluminum. If it doesn’t break it up in a few hours I’ll scrap the idea.
Seems like one of those things where it would be great if it worked, but might end up being a time sink and safety hazard.
Did some further research and seems guys on youtube are making it pretty easily from aluminum foil and it’s quite stable (much less of a hazard than AI was claiming).
The trick seems to be to use a torch to make it brittle, and they aren’t using alcohol, which will make more of a slurry and it seems I want things super dry in the grinding environment.
Many tumblers use water, optionally with a splash of specialized non-foaming soap. If you ever need to control dust again, I’d suggest something closer to that as a starting point.
You might look into polishing “cold cast” resin parts for more info. I know people have done lots of dice and such, usually with mixed results unfortunately.
My best guess is that you’ll get an ok finish at best after some trial and error. Definitely recommend doing little testers, resin is expensive.
But I do have to wonder, if you need the high shine that solid aluminum gives you…why not try solid aluminum?
That’s not meant to be a snarky comment, I’m more just interested in what kind of geometry or aesthetic you’re trying to achieve that can’t be milled
Would mostly be a speed of implementation type of thing.
Aluminum inlays can be used to charge a lot more money for wood based products, but the downside is that they require small end mills (0.5mm in some cases), that take forever to mill out details, plus to make it worse, vbits are potentially off the table.
So if I use a vbit in wood, then dump in some aluminum powder or mica + resin the results might be nice. I use dollar store epoxy, costs $3 for a vile, sets in 5 mins and you just reseal what do don’t use.
I did a quick test (I’m aware it’s a very crappy test) but just to give a very basic idea if it’s worth pursuing this strategy. I dumped full untouched chips into the milled out area with resin (terrible test because of the size of the chips). I just wanted proof of concept to see how it would look when sanded. Most of the chips didn’t even get into the pocket, but where it did showed very good potential.
Image attached, its worth the effort trying to make it work IMO.
Top left: resin + dark mica (resin was improperly mixed, wasn’t 50/50 so it scuffed result)
Bottom left: resin + aluminum CHIPS
Right of the aluminum chips is copper chips + resin
All others are stain variations.
If I can get that aluminum to look totally solid, or at least somewhat aesthetic in the vbit pass, it will be a game changer as far as shooting out higher quality products faster IMO.
To carve that horse head out of 1/16" aluminum would take probably 1+ hour.
I was actually about to post that Elemental Maker video, but you beat me to it. Generally the finer the particle size of metal the darker it gets. If you look halfway through the video when he stops it the powder is still fairly shinny but had bigger chunks still in it. It isn’t till he gets it down to the super small particle size that he was after that it gets super dark. You should stop sooner and just sift out the bigger chunks.
As for your issues with ball milling it, it really comes down to the temper of the material and the overall hardness. You want it as brittle / hard as possible which is different from the temper you have for machinability. I am assuming you have been machining 6061 which is a ductile alloy of aluminum and as such is not very brittle. This makes it a poor choice for ball milling. I am pretty sure that bringing 50 LBS of 6061 chips to a recycling plant and taking the money to buy a bunch of cheap aluminum foil would be the better option.
From my own experience with leaf/foils I wouldn’t say it’s easier or faster. Admittedly, that might be a skill issue on my part though
That said, it’s definitely cheaper and has the potential for a much more interesting/unique aesthetic, so it might be worth looking into
The 3D printing is an interesting idea if the design will be made in some quantity, otherwise I’m guessing the cost of shipping and setup for one offs would kill any profitability
Sidenote for resin stuff: I’ve been part of various resin communities for quite some time now (prototyping, small batch production, crafts, etc…)
The commonality across all resin related activity is resin sensitivity.
Chances are if you work with it long enough, you’ll develop a sensitivity. Even with moderate safety precautions like gloves and a somewhat ventilated area that sensitivity tends to build up.
Fortunately, I’ve been around the same communities long enough to see it happen over very long time frames. Some folks are very careful and it took years to develop, but it still tends to develop…I think of it like riding a motorcycle, it’s not if you lay it down, it’s when…and if it never happens, it’s not because you’re good, it’s because you’re lucky
I’m not saying don’t work with it and I’m not telling you to go out and buy a hazmat suit. Just be aware of the symptoms and keep them in mind as you work with resin more. Some folks take awhile to realize they’ve developed a sensitivity simply because it can take 12+ hours for symptoms to show after exposure (I’ve seen this play out quite a few times)
The issue is that I have 1 section of the work piece that will have a solid aluminum inlay with text
Then I’ll have 1 section of the work piece thats got an epoxy inlay which is an image
Both need to look like identical aluminum, I have some mica powder but how well can the mimic the aluminum inlay above?
Currently the best method seems like:
Hit chips with blow torch to make them brittle
Put chips into coffee grinder
Pass ground chips into a filter
Been distracted with all kinds of other stuff, but I got some fairly fine powder made just by using a coffee grinder and crude home made filter. I’m currently waiting on a level 100 mesh which should keep the particle size just right.
I have some epoxy mixed with the powder I put into a test piece, it’s curing right now. Need to wait for cure, mill off excess then sand. I’ll share the results when it’s ready.
Why go through all this effort, there are vendors who stock flake aluminum powder . Google “flake aluminum power” Multiple colors and intensities priced per pound less than $25 @ https://powderbuythepound.com/
Tom
(I’ve seen this play out quite a few times)